Unrooting GS2 I9100 international version

[DeStorm]

Hi all,

I want to unroot my gs2 so that I can update my phone from gingerbread 2.3.4 to ICS using kies.
What is the best way to unroot my phone with minimal chance of it becoming brick
My CSC is OXA.

If kies doesn't work after unrooting, do I then use the odin flash etc to install the ICS and if I want to root ICS, where can then find the best instructions to do this.

Thank you in advance

 

[Usta]

1. Get Odin
2. Use it to flash an official firmware (see for example SamMobile Firmware Page).
3. See rooting instructions for ICS here: [TUTORIAL] Root access for ICS on I9100G - xda-developers